Hello Sandep, - Page 2

paulbroomfield · ‎09-25-2013

Hi guys,

I'm rather new to this so I might be asking some silly questions.

We have just bought two 24port 3850, and I'd love to get them work as a stack. I've plugged in the stackwise, configured VLAN's and Syslog. I boot the master then the slave and it joins the stack fine.

My problem is that the master stays as active and the slave sits there waiting patiently doing nothing, ready for the master to die and for the slave to take over.

It'd be great to get these guys working together in a traditional stack.

After a bunch of reading I can't find the answer I'm looking for, I come across bits about Level 3 licensing, but I'm still not clear about what I actually have to do.

Please could someone point me in the right direction.

thanks!

Paul

glen.grant · ‎09-25-2013

you have no L3 routing setup except vlan 2 so you wouldn't be able to ping between devices on switch 2 because those ports are all in vlan 1 . So make sure ip routing is turned on for the stack , assign gateway addresses to "interface vlaN 1 AND VLAN 3 . If testing between pc's then make sure all pc firewalls are turned off before testing . The stack appears to be working normally as you can see all the ports in the stack , switch 1 is the master. No you wouldn't be able to ping from switch 2 console port as it's not the current master for the stack.Add addresses to these

nterface Vlan1 needs address

no ip address

ip broadcast-address 192.168.15.255

!

interface Vlan2

ip address 192.168.0.251 255.255.255.0

!

interface Vlan3 ---> needs address , these are the gateways for the vlans .

no ip address

!

Not sure what you mean with this.

What we have done.

- configured matching vlan's on each switch ---> ???? You only configure the master switch which controls the whole stack...

.

Richard Primm · ‎09-25-2013

Hello Paul,

On the 3850 we have moved to a new (well new to the 3K platform) technology in which we have the standby fully synced with the master for high availability. If you have ever used one of our chassis switches (4500, 6500) with dual supervisors, it would be along those lines. If you run a "show redundancy" you should see the switches in "SSO" or hot standby, which is what you want to see. This basically means that our standby is actively waiting to take over control in the case that the master fails (hitless). So to answer your question, they kind of work together

Your stack speeds will be 240Gbps or 480 if in a ring.

You can use the following commands to verify your stacking:

3850-stack#show switch detail

3850-stack#show switch stack-ports summary

++ If you want to verify that indeed it will take over as expected, then you can simpy run:

3850-stack#redundancy force-switchover ** please note this will swap the master/standby and reload the old master

++++++++++++++++++++++++++++++

Example of show redundancy

3850-stack#show redundancy

Redundant System Information :

------------------------------

Available system uptime = 2 days, 17 hours, 46 minutes

Switchovers system experienced = 0

Standby failures = 0

Last switchover reason = not known

Hardware Mode = Duplex

Configured Redundancy Mode = SSO <<-------- Look for this (if it says RPR, then investigate why)

Operating Redundancy Mode = SSO

Maintenance Mode = Disabled

Communications = Up

Current Processor Information :

------------------------------

Active Location = slot 2

Current Software state = ACTIVE

Uptime in current state = 2 days, 17 hours, 46 minutes

Image Version = Cisco IOS Software, IOS-XE Software, Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version 03.02.03.SE RELEASE SOFTWARE (fc1)

Technical Support: http://www.cisco.com/techsupport

Compiled Thu 19-Sep-13 15:25 by prod_rel

BOOT = flash:packages.conf;

Configuration register = 0x102

Peer Processor Information :

------------------------------

Standby Location = slot 1

Current Software state = STANDBY HOT <<<----------------- This is what it should say

Uptime in current state = 2 days, 17 hours, 42 minutes

Image Version = Cisco IOS Software, IOS-XE Software, Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version 03.02.03.SE RELEASE SOFTWARE (fc1)

Technical Support: http://www.cisco.com/techsupport

Compiled Thu 19-Sep-13 15:25 by prod_rel

BOOT = flash:packages.conf;

Configuration register = 0x102

Hope that helps

Luke

paulbroomfield · ‎09-25-2013

Hi all,

Thanks for all your help so far.

So to clarify the problem.

- we have two switches connected with two stackwise 480's

- both switches have 2 vlans each, lets call them VLAN1 and VLAN2

- we'd love VLAN1 on both switches talking to each other and likewise for VLAN2, therefore having isolation between VLAN's and running both on both switches, i.e. vertically vlan'd switches.

What we're experiencing.

- the slave switch joins the stack and marks itself as STANDBY HOT

- the master VLAN1 can not see devices plugged into the slave VLAN1, likewise for the VLAN2's

The goal.

- to have both switches active at the same time for redundancy.

- each of our servers have mutliple bonded NIC's, one going to master VLAN1 and the other to slave VLAN1 etc.

- being able to turn off one of the switches and everything still work.

- being able to pull out one ethernet cable and traffic to flow across the other nic/switch

What we have done.

- configured matching vlan's on each switch

- plugged in the stacking cable and watched the slave join the stack

- plugged a laptop into the slave and tried to ping something in the master stack, watched it fail.

thanks again,

Paul

Sandeep Choudhary · ‎09-25-2013

HI Paul,

First of all:

1. Make sure the IOS feature set is the same on all core stack switches.

On the master:

show switch

example return:

*1 Master e4d3.f184.ad80 15 1 Ready

2 Member e4d3.f159.4580 15 1 Ready

example

conf t

sw 2 prior 14

end

wr mem

reload

2. Make sure the switch priority is lower than the master and other members, and set the number...

3. Make sure they are connected like below. (switch 1and switch 2 powered off, )

[Switch 1]----Stack cable 1 to 2

[Switch 3]---------Stack cable 2 to 1

4. Power the new switch up. confirm the stack status with show switch, then configure the ports.

Regards

Hope it helps.

jayesh.acharya1 · ‎07-29-2017

Hello Sandep,

I have configured as u have mentioned. but when i turn of my active switch the standby switch stops working..plz help

jayesh.acharya1 · ‎07-29-2017

Hello Paul,

Have you implemented HA in Cisco 3850???

I have two switch with stack cable...but I unable to work in HA environment. If primary switch fails standby sw doesn't work...

paulbroomfield · ‎09-30-2013

Hi,

Thanks for everyones help.

After more digging around I think I might need to configure interVLAN routing. That way the Vlan's on my master switch will be able to comunicate with the vlans on my slave switch.

Feel free to correct me though.

thanks,

paulbroomfield · ‎09-30-2013

Oh actually, I think I just had a face-palm moment

Seeing when configuring stacked switches those changes affect all switches in the stack. I should be creating a VLAN to contain X amount of ports from switch 1 and switch 2.

That way I end up with a 'vertical' split.

I haven't tried this but I imagine the comands would look something like this:

vlan 2

name FirstVLAN

interface range gigabitEthernet 1/0/1-12

interface range gigabitEthernet 2/0/1-12

switchport access vlan 2

vlan 3

name SecondVLAN

interface range gigabitEthernet 1/0/13-24

interface range gigabitEthernet 2/0/13-24

switchport access vlan 3

or something like that.

My original, and incorrect thinking, was that by setting up each switch with match VLAN names, those VLANs would some how magically, talk to each other verticallly.

cheers,

3850 - How to Stack, need some help please.